Shining light on a previously little-known topic is the motivation behind the popular investigative NBC series "To Catch a Predator," an NBC news anchor said Wednesday night.

Chris Hansen, who is most famous for his role as the show's anchor, spoke for an hour in a packed K-State Student Union Ballroom.

The series involves luring men who are potential sexual predators into online conversations with actors pretending to be underage girls. The actors get the men to agree to a meeting at a house, and when the men arrive, Hansen appears and confronts them about what they are doing in the house.

Hansen began his lecture with jokes and the story of Conan O'Brien's pre-Emmy parody of his reports. Hansen said he likes all of the "buzz" his show generates but is careful not to overdo his celebrity cameos.

Hansen also gave a short history of the "To Catch a Predator" series.

"The whole thing started about four years ago when a friend of mine told me about the Perverted Justice Web Site," Hansen said.

Perverted Justice is a group that has been running sex predator stings since June 2004 and teamed up with NBC to broaden the scope of its effectiveness.

Hansen said that there have been many memorable busts, including one in which the alleged sex offender walked into the house completely naked.

"Never in my four years of taking classes at Michigan State University did they teach you how to interview a naked man," Hansen said.

Hansen also said the man was caught again the next day trying to set up meetings with underage girls on the Internet.

Hansen said that he and his partners have executed 12 separate stings and exposed more than 300 would-be sexual predators.

"All but a couple dozen have been or are being prosecuted," Hansen said. "Of those, 140 have either pleaded guilty or have been found guilty by a judge and jury."

Hansen also said that the punishments for the convicted have ranged from probation and registration as a sex offender, all the way up to a man in Georgia who received 14 years in federal prison.

When Hansen walked up to the podium, he was greeted by cheers that turned into a standing ovation.

The event's organizers knew Hansen's celebrity status would be enough to get students into the seats but were caught off guard by the number of people who attended.

"Based on his popularity, we expected a lot of people to show up," Powell Runyon, junior in construction science, said. "We talked to facilities, and we were prepared to set up extra chairs at the back of the room."

That popularity was enough to coax many into the seats.

"I wanted to see what he said about 'To Catch a Predator,'" said Jerrod Anderson, senior in sociology.